Celiprolol vs propranolol in unstable angina pectoris: a double-blind, randomized, parallel-group study.

Celiprolol, a novel beta blocker, may be more effective than propranolol in unstable angina pectoris because of both its beta-1-receptor selectivity and its vasodilator property. In the present report 53 patients with angiographic coronary artery disease but uncompromised left ventricular function and with electrocardiographically documented recurrent angina pectoris in spite of bed rest, aspirin, and repeated sublingual administration of nitroglycerin were studied. They were randomized for treatment with equipotent doses of either the nonselective beta blocker propranolol (80 mg/day) or the selective beta blocker with beta-2-agonistic property, celiprolol (200 mg/day) during one week. Angina frequency was higher in the propranolol group (P < 0.01), whereas myocardial oxygen demand as estimated by the double product (DP = SBP x HR, systolic blood pressure x heart rate) was equally reduced by the two beta blockers. Forearm blood flow was essentially higher in the celiprolol group (P < 0.001). A stepwise logistic regression analysis showed that the beneficial effects of the beta blockers were largely dependent on their effect on peripheral flow, in addition to reduction of the double product. The authors conclude that (1) Both celiprolol and propranolol largely reduce angina pectoris frequency in unstable angina pectoris. (2) Celiprolol contributes to nearly complete relief in three times as many patients as propranolol; after adjustment for double product or for systolic blood pressure plus heart rate it performs even eight times better. (3) The similar effects of the two compounds on the double product and the essentially different effects on peripheral flow support the conclusion that celiprolol exerts its beneficial effect to a large extent through its vasodilator property.